Flat wire motor uniform temperature stator system based on heterogeneous micro-channel array heat pipes

Abstract

The invention discloses a flat wire motor uniform temperature stator system based on heterogeneous micro-channel array heat pipes, and the system comprises a stator core which is provided with a plurality of stator grooves, and the inner walls of three surfaces of each stator groove are respectively provided with a heat pipe embedding groove; a plurality of heterogeneous micro-channel array heat pipes, each heterogeneous micro-channel array heat pipe is installed in the heat pipe embedding groove of the corresponding stator groove to form a U-shaped thermal coupling path, and each heterogeneous micro-channel array heat pipe is provided with a bidirectional thermal path which takes phase change heat transfer as a main part and takes capillary driving as an auxiliary part; when the windings are embedded into the corresponding stator grooves, the windings are isolated from the heterogeneous micro-channel array heat pipes through insulation structures. According to the invention, winding three-surface fitting type near-field heat conduction can be realized, and the internal hot spot leading-out efficiency and temperature uniformity of the winding are remarkably improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of motor thermal management, and particularly relates to a flat wire motor uniform temperature stator system based on a heterogeneous microchannel array heat pipe. BACKGROUND

[0002] With the continuous development of new energy vehicles and engineering machinery electric drive systems towards high power density, high efficiency and high reliability, the thermal management problem in the motor is increasingly prominent. In particular, in the permanent magnet synchronous motor using the flat wire concentrated winding structure, there is a complex local heat accumulation phenomenon between the stator windings. The traditional water jacket cooling method is difficult to realize the rapid temperature equalization and hot spot suppression of the stator winding area due to the long heat path and low internal heat conduction efficiency of the winding.

[0003] The existing thermal management methods mainly focus on stator shell water cooling, stator core oil immersion cooling or structure heat conduction optimization. Although the overall heat exchange capacity is improved to a certain extent, there are still the following problems: (1) The heat transfer path from the winding interior to the cooling medium is far, the response is slow, the thermal resistance is high, and it is difficult to adapt to high heat flux density occasions; (2) The heat distribution is uneven in the three-sided slot area (tooth wall and yoke on both sides of the slot opening), and the hot spot is easily concentrated in the tooth root area, forming the risk of accelerated aging of the winding insulation; (3) There is a lack of system-integrated phase change heat conduction means, which cannot balance the rapid response and heat distribution uniformity; (4) The conventional heat conduction materials (such as heat conduction pads, insulating paper, etc.) have low heat conductivity and lack directional heat transfer capability, and cannot realize active heat regulation.

[0004] At present, there is no integrated application of heterogeneous microchannel structure and ultra-thin phase change heat pipe to the full-area temperature equalization design of flat wire winding interior. How to construct a compact, efficient and compatible stator winding internal thermal management structure to adapt to the high heat flux density and dynamic working condition requirements has become one of the key bottlenecks of the current motor thermal management technology development. Therefore, the application proposes a flat wire motor uniform temperature stator system based on a heterogeneous microchannel array heat pipe, which embeds an H-shaped heat pipe array in the three-sided slot to construct a capillary-driven phase change heat transfer path inside the stator, effectively improves the internal thermal management efficiency and temperature control precision of the stator, breaks through the adaptation limit of the traditional cooling structure to the high-performance electric drive system, and has significant engineering application value.

[0005] Chinese invention patent application CN116365792A discloses a motor heat dissipation structure based on a heat spreader and a phase change heat pipe. The structure includes several through slots formed on the outer surface of the stator core, with heat spreaders mounted on these slots. The heat spreaders include I-shaped and / or L-shaped heat spreaders, and a phase change heat pipe is located at the winding end. The winding is connected to the stator core. This design allows for the creation of multiple through slots on the outer surface of the stator core to accommodate I-shaped or L-shaped heat spreaders, or both shapes, depending on the actual heat dissipation requirements of the motor. By using through slots on the stator core in conjunction with the heat spreaders and by placing phase change heat pipes at the winding ends, the heat dissipation structure can be streamlined while effectively reducing the temperature of the overhanging windings and improving the heat dissipation efficiency of the motor stator core, thereby further enhancing the motor's overall heat dissipation efficiency. While this scheme incorporates a combination of a heat spreader and phase-change heat pipes for external heat management of the stator core, it primarily deploys heat on the external surface of the stator core and at the winding ends, failing to penetrate the internal three-sided slot structure of the stator. This makes it unable to address the issue of hot spot accumulation within the stator winding body (especially in the area where the teeth and yoke meet). Furthermore, the heat spreader structure, using I-type or L-type heat pipes installed within the slots, significantly alters the stator structure, resulting in complex structural modifications, high difficulty in standardized assembly, and a single heat dissipation path.

[0006] Chinese invention patent application CN119561315A discloses a stator heat dissipation structure and design method for a phase change heat transfer motor, including a stator core, copper wire windings, and a flattened phase change heat transfer device. The copper wire windings are disposed inside the stator core, and the flattened phase change heat transfer device is disposed in a slot within the radial interior of the copper wire windings that contacts the stator core. The design method for the heat dissipation structure is also disclosed. This solution utilizes the aforementioned heat dissipation structure and design method to develop thermal control technology for the motor stator windings based on the phase change heat transfer device, achieving a significant reduction in peak motor temperature, enhanced motor temperature uniformity, and safe operation under high overload conditions. While this solution proposes embedding the flattened phase change device into the radial slots of the windings and combining this with the design method for heat dissipation simulation optimization, thus improving thermal control capabilities, its phase change structure is a single configuration, lacking an effective management mechanism for the internal gas-liquid recirculation path. For example, it does not form an independent condensation channel, the capillary recirculation structure is unclear, and it cannot achieve rapid gas-liquid separation and capillary recirculation drive. Furthermore, the scheme does not employ a heterogeneous structure design, making it difficult to adapt to the complex heat source distribution within the winding's internal space. It cannot achieve "differentiated temperature control" for regions with different heat flux densities, and its response stability and temperature control uniformity under high-speed or variable load scenarios still need optimization.

[0007] Chinese invention patent application CN112994357B discloses a method for improving the cooling of a motor stator. This method includes adding a new set of cooling channels to the existing water circulation cooling system of the motor stator, forming a dual-channel structure; controlling the positions of the inlet and outlet of the new cooling channels; controlling the formation of a cross-cooling structure between the new and old cooling channels, while maintaining their independent structure; forming a first filling cavity and a second filling cavity inside the new and old cooling channels respectively; and filling the first and second filling cavities with a composite phase change material to form a conductive layer. The combined flow channels formed by the new and old cooling channels provide cross-cooling, ensuring that both ends of the stator receive cooling at the same temperature. The heat exceeding the temperature at the outlet of the old cooling channel is cooled by the inlet of the new cooling channel, achieving cross-complementary cooling and bringing the axial temperature of the heated iron core towards equilibrium. This solution focuses on improving the overall cooling capacity of the motor stator by constructing dual cooling channels, filling with composite phase change material, and forming cross-cooling pathways to achieve balanced axial heat flow control. While this approach offers some advantages in terms of axial cooling uniformity in the stator, it doesn't penetrate deeply into the localized hotspot areas within the windings, still relying primarily on external water cooling. This limits its ability to handle the high heat density areas of the stator's three-sided slots. Furthermore, the heat transfer path of the composite material-filled "conductive layer" is relatively long, resulting in a slow thermal response. It also fails to create an efficient closed-loop heat transfer system that facilitates rapid heat conduction, phase change, condensation, and capillary reflux in localized hotspots, leaving its thermal management capabilities under high overload conditions insufficient. Summary of the Invention

[0008] To address the aforementioned issues, this invention proposes a flat wire motor temperature equalization stator system based on heterogeneous microchannel array heat pipes. This system aims to solve key technical problems in existing water-cooled flat wire permanent magnet synchronous motor stator heat dissipation structures, such as difficulty in efficiently discharging local hot spots, large temperature difference between the three sides of the winding, slow thermal response, poor integration of phase change elements, and insufficient structural adaptability.

[0009] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution: A flat wire motor temperature-equalizing stator system based on heterogeneous microchannel array heat pipes, comprising: The stator core has several stator slots, and each stator slot has a heat pipe mounting groove on three inner walls. Several heterogeneous microchannel array heat pipes are installed in the heat pipe mounting slots of the corresponding stator slots to form a U-shaped thermal coupling path. Each heterogeneous microchannel array heat pipe has a bidirectional thermal path with phase change heat transfer as the main method and capillary drive as the auxiliary method. The windings are isolated from the heterogeneous microchannel array heat pipes by an insulating structure after they are embedded in the corresponding stator slots.

[0010] Optionally, the stator slot includes a left tooth side slot, a stator yoke slot, and a right tooth side slot arranged in sequence, and the left tooth side slot and the right tooth side slot are arranged opposite to each other; The heterogeneous microchannel array heat pipe includes a first sub-heat pipe, a second sub-heat pipe, and a third sub-heat pipe; the first and second sub-heat pipes are arranged opposite to each other and are respectively disposed in heat pipe mounting slots on the left tooth side groove and the right tooth side groove; the third sub-heat pipe is disposed in a heat pipe mounting slot on the stator yoke groove.

[0011] Optionally, the first sub-heat pipe, the second sub-heat pipe, and the third sub-heat pipe have the same structure, each including: a shell, and a first wick, a second wick, and a plurality of reflux columns disposed within the shell; The first liquid-absorbing core is located at the first end of the shell, forming an evaporation end; The second absorbent core is disposed opposite to the first absorbent core at the second end of the housing, forming a condensation end; Each reflux column is arranged sequentially along the extension direction of the first and second liquid-absorbing cores, and its two ends are respectively connected to the first and second liquid-absorbing cores, dividing the inner cavity of the shell into several vapor chambers, each of which is a fully enclosed phase change heat transfer chamber. The first wick, the second wick, and the reflux column are all porous media, and the mesh size of the first wick is greater than that of the second wick; the pore size of the holes on the reflux column decreases in a stepwise manner from the evaporation end to the condensation end. The working fluid is impregnated inside the first suction core, the second suction core, and each reflux column.

[0012] Optionally, the evaporation end is attached to the winding, and the condensation end is attached to the stator core. The evaporation end receives the heat conducted from the winding to the stator core wall. After the working fluid is vaporized, it migrates along the vapor chamber to the condensation end. After cooling, it condenses into a liquid. The liquid is returned to the evaporation end through the first liquid wick, the second liquid wick, and the return column, forming a closed phase change heat transfer cycle.

[0013] Optionally, the surface of each reflux column is provided with a hydrophilic coating.

[0014] Optionally, the first sub-heat pipe, the second sub-heat pipe, and the third sub-heat pipe all have H-shaped cross-sections, and each end is provided with a groove for cooperating with the corresponding heat pipe mounting groove.

[0015] Optionally, the thickness of the housing is 0.8mm to 1.2mm, its length is consistent with the effective core length of the stator, and its width is 1 to 3mm less than the width inside the stator slot.

[0016] Optionally, the heterogeneous microchannel array heat pipes and the heat pipe mounting slots are fixed together by interference fit, welding or adhesive to form a thermal interface.

[0017] Optionally, the outer surface of each heterogeneous microchannel array heat pipe is coated with a magnetic field conductive coating.

[0018] Optionally, the working fluid is degassed deionized water or a mixture of alcohols.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention integrates heterogeneous microchannel array heat pipes onto three sides of the stator slot, constructing a highly efficient uniform temperature heat dissipation system based on "U-shaped bonding—three-dimensional heat conduction—phase change heat transfer," which has the following beneficial effects: (1) Break through the traditional heat diffusion bottleneck and achieve uniform temperature across the entire turn / inter-turn area. By utilizing the rapid phase change heat transfer characteristics of heterogeneous microchannel array heat pipes, the heat in the near field of the three sides of the stator winding can be quickly captured and synchronously transferred, significantly reducing the probability of hot spot formation in the winding, reducing the temperature difference between turns by more than 30%, and effectively suppressing the risk of local overheating failure.

[0020] (2) Construct a multi-level collaborative heat dissipation path to improve thermal control capability under high load. The evaporation end is directly attached to the winding, and the condensation end is attached to the stator core, which, together with the water-cooled shell, achieves two-stage cooling. The microchannel system composed of the reflux column and the stepped liquid suction core (i.e. the first liquid suction core and the second liquid suction core) realizes bidirectional partitioned flow of vapor and liquid, which significantly improves the stability and response capability of the heat dissipation system under complex working conditions such as variable load, high frequency, and tilt.

[0021] (3) The heterogeneous heat pipe and stator structure are highly integrated to meet the design requirements of compact space motors. The first, second, and third sub-heat pipes of the H-type design all adopt an ultra-thin structure with a thickness of 0.8~1.2mm. They are embedded in the stator slots without increasing the stator volume. After being arranged on three sides, they form a close-fitting U-shaped heat network without affecting the integrity of the iron core structure. This design is particularly suitable for engineering machinery and electric drive systems of new energy vehicles where installation space is limited and heat flux density is concentrated.

[0022] (4) Ensure stable electromagnetic performance and overcome magnetic flux interference caused by heat pipe insertion. By designing a magnetic flux-conducting coating on the surface of a heterogeneous microchannel array heat pipe, efficient thermal management is achieved while maintaining magnetic circuit continuity, effectively avoiding electromagnetic performance loss caused by traditional metal heat dissipation structures, and keeping motor efficiency reduction to within 1%. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a schematic diagram of the structure of a flat wire motor temperature-equalizing stator system based on a heterogeneous microchannel array heat pipe according to an embodiment of the present invention; Figure 2(a) is a schematic diagram of the stator core with built-in heat pipe mounting slot according to an embodiment of the present invention; Figure 2(b) is a schematic diagram of a heterogeneous microchannel array heat pipe according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the planar structure of a stator core according to an embodiment of the present invention; Figure 4(a) is a schematic diagram of the structure of a single stator core slot according to an embodiment of the present invention; Figure 4(b) is a schematic diagram of a single heterogeneous microchannel array heat pipe structure according to an embodiment of the present invention; Figure 5(a) is a schematic diagram of the structure of the H-type heterogeneous microchannel array heat pipe in the stator yoke groove of an embodiment of the present invention; Figure 5(b) is a schematic diagram of the structure of an H-type heterogeneous microchannel array heat pipe with toothed grooves according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the internal structure of the H-type heterogeneous microchannel array heat pipe in the stator yoke slot of an embodiment of the present invention; Figure 7 This is a schematic diagram of the internal structure of an H-type heterogeneous microchannel array heat pipe with toothed side grooves according to an embodiment of the present invention; Explanation of reference numerals in the attached figures: 1. Stator core; 2. Winding; 3. Heterogeneous microchannel array heat pipe; 11. Stator core yoke; 12. Stator slot; 13. Stator yoke heat pipe mounting slot; 14. Stator tooth heat pipe mounting slot; 31. Third sub-heat pipe; 32. First sub-heat pipe; 311. Evaporation end shell plate of yoke heat pipe; 312. Evaporation end wick of yoke heat pipe; 313. Capillary reflux column of yoke heat pipe; 314. Condensation end wick of yoke heat pipe; 315. Condensation end shell plate of yoke heat pipe; 316. Microchannel vapor chamber of yoke heat pipe; 321. Evaporation end shell plate of tooth heat pipe; 322. Evaporation end wick of tooth heat pipe; 323. Capillary reflux column of tooth heat pipe; 324. Condensation end wick of tooth heat pipe; 325. Condensation end shell plate of tooth heat pipe; 326. Microchannel vapor chamber of tooth heat pipe. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may include different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0026] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0027] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0028] The application principle of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] like Figures 1-7As shown, this invention provides a flat wire motor temperature-equalizing stator system based on a heterogeneous microchannel array heat pipe 3, comprising: The stator core 1 has several stator slots 12 along its circumference, and each stator slot 12 has a heat pipe mounting groove on its three inner walls. Several heterogeneous microchannel array heat pipes 3 are installed in the heat pipe mounting slots of the corresponding stator slots 12, forming a U-shaped thermal coupling path, which enables the entire system to have symmetrical heat conduction and three-dimensional heat conduction capabilities; each heterogeneous microchannel array heat pipe 3 is equipped with a working fluid, which has a bidirectional thermal path with phase change heat transfer as the main method and capillary drive as the auxiliary method. Several windings 2 are embedded in the corresponding stator slots 12 and are isolated from the heterogeneous microchannel array heat pipes 3 by an insulating structure, while maintaining an effective thermal coupling path.

[0030] In the above scheme, the phase change heat transfer characteristics of the heterogeneous microchannel array heat pipe 3 are used to achieve rapid capture and synchronous transfer of near-field heat on three sides of the winding 2, which can significantly reduce the probability of hot spot formation in the winding 2, reduce the temperature difference between turns by more than 30%, and effectively suppress the risk of local overheating failure.

[0031] In one specific embodiment of the present invention, the winding 2 is arranged in a 6-layer or higher configuration and has a rectangular cross-section.

[0032] The above scheme specifies the arrangement of winding 2 to facilitate subsequent production and preparation.

[0033] In a specific embodiment of the present invention, the stator slot 12 includes a left tooth side slot, a stator yoke slot and a right tooth side slot arranged in sequence, and the left tooth side slot and the right tooth side slot are arranged opposite to each other; the stator yoke slot is provided on the stator core yoke 11. The heterogeneous microchannel array heat pipe 3 includes a first sub-heat pipe 32, a second sub-heat pipe, and a third sub-heat pipe 31; the first sub-heat pipe 32 and the second sub-heat pipe are arranged opposite to each other and are respectively disposed in heat pipe mounting slots on the left tooth side groove and the right tooth side groove; the third sub-heat pipe 31 is disposed in a heat pipe mounting slot on the stator yoke groove.

[0034] In the above scheme, the specific cooperation relationship between the stator slot 12 and the heterogeneous microchannel array heat pipe 3 is defined. By integrating the heterogeneous microchannel array heat pipe 3 onto three sides of the stator slot 12 (left tooth side slot, stator yoke slot, and right tooth side slot), a highly efficient uniform temperature heat dissipation system of "U-shaped bonding - three-dimensional heat conduction - phase change heat transfer" is constructed to achieve rapid heat dissipation from the three sides of the winding 2 in the near field. In the specific implementation process, the heat pipe mounting slot installed on the stator yoke slot can be defined as the stator yoke heat pipe mounting slot, and the heat pipe mounting slots installed on the left tooth side slot and the right tooth side slot can be defined as the stator tooth heat pipe mounting slots.

[0035] In a specific embodiment of the present invention, the first sub-heat pipe 32, the second sub-heat pipe and the third sub-heat pipe 31 have the same structure, each including: a shell, and a first liquid wick, a second liquid wick and a plurality of reflux columns disposed in the shell; The first liquid-absorbing core is located at the first end of the shell, forming an evaporation end; The second absorbent core is disposed opposite to the first absorbent core at the second end of the housing, forming a condensation end; Each reflux column is arranged sequentially along the extension direction of the first and second liquid-absorbing cores, and its two ends are respectively connected to the first and second liquid-absorbing cores, dividing the inner cavity of the shell into several vapor chambers, each of which is a fully enclosed phase change heat transfer chamber. The first liquid-absorbing core, the second liquid-absorbing core, and the reflux column are all porous media, and the mesh size of the first liquid-absorbing core is greater than that of the second liquid-absorbing core. In specific implementation, the first liquid-absorbing core adopts a high capillary force liquid-absorbing core, which can be selected from high-mesh sintered copper powder or metal mesh, to quickly absorb the heat transferred from the winding 2 and promote the vaporization of the working fluid; the second liquid-absorbing core adopts a low flow resistance and high permeability liquid-absorbing core, which can be selected from low-mesh sintered metal bodies, to cooperate with the water-cooled shell to achieve rapid condensation and heat release. The aperture of the holes on the reflux column decreases in a stepped manner from the evaporation end to the condensation end. Since the capillary force is much greater than the gravity, the working fluid can be transported from the condensation end to the evaporation end even under anti-gravity conditions. This enables bidirectional vapor-liquid flow, enhances the smoothness of high-speed liquid return, and improves the stability of the heterogeneous microchannel array heat pipe 3 under variable load and angle tilt conditions. Each reflux column also serves as a dual function of mechanical support and liquid return channel, effectively preventing heat pipe bulging or deformation failure. The working fluid is impregnated inside the first suction core, the second suction core, and each reflux column.

[0036] The above scheme provides a detailed description of the specific structures of the first sub-heat pipe 32, the second sub-heat pipe, and the third sub-heat pipe 31. In practical applications, the evaporation end is attached to the winding 2, and the condensation end is attached to the stator core 1. The evaporation end receives heat conducted from the winding 2 to the wall of the stator core 1. After the working fluid is vaporized, it migrates along the vapor chamber to the condensation end. After cooling, it condenses into a liquid. The liquid is returned to the evaporation end through the first wicking core, the second wicking core, and the return column, forming a closed-loop phase change heat transfer cycle.

[0037] In one specific embodiment of the present invention, the surface of each reflux column is provided with a hydrophilic coating.

[0038] In the above scheme, by applying a hydrophilic coating to the surface of each reflux column, the capillary liquid absorption capacity can be effectively enhanced.

[0039] In one specific embodiment of the present invention, the cross-sections of the first sub-heat pipe 32, the second sub-heat pipe and the third sub-heat pipe 31 are all H-shaped, and each end is provided with a groove for cooperating with the corresponding heat pipe mounting groove.

[0040] In one specific embodiment of the present invention, the thickness of the housing is 0.8mm to 1.2mm, its length is consistent with the effective core length of the stator, and its width is 1 to 3mm less than the width inside the stator slot 12.

[0041] Based on the above design, the first sub-heat pipe 32, the second sub-heat pipe, and the third sub-heat pipe 31 form an integrated H-shaped thermal network, resulting in a highly coupled, highly responsive, and highly balanced internal heat dissipation system for the stator, significantly improving the thermal conductivity between the winding 2 and the heat dissipation surface. The heterogeneous microchannel array heat pipe 3, in its embedded state, forms a "thermal sandwich" with the three sides of the winding 2, rapidly transferring heat to the external water-cooled housing through a three-dimensional thermal conduction path in a motor structure where the axial cooling path is limited.

[0042] In one specific embodiment of the present invention, the heterogeneous microchannel array heat pipe 3 and the heat pipe mounting groove are fixed together by interference fit, welding or adhesive to form a thermal interface.

[0043] Based on the above design, the flat wire motor temperature uniformity definition system of the present invention has good vibration durability performance, stable structure, and can meet the vibration life requirements of electric drive system.

[0044] In one specific embodiment of the present invention, the outer surface of each heterogeneous microchannel array heat pipe 3 is coated with a magnetic field conductive coating. In specific implementation, the magnetic field conductive coating can be made of ferrite composite material.

[0045] In the above scheme, by coating the outer surface of each heterogeneous microchannel array heat pipe 3 with a magnetic field conduction coating, the continuity of the magnetic flux path between windings 2 is improved without affecting the heat conduction performance. This compensates for the thin magnetic flux area that may be caused by traditional heat pipe embedding, effectively improving the electromagnetic performance of the motor. It also compensates for the magnetic flux interruption area that was originally caused by heat pipe insertion, minimizes the stator magnetic reluctance change, and ensures the stability of the motor's electromagnetic performance.

[0046] In one specific embodiment of the present invention, the working fluid is degassed deionized water or a mixture of alcohols.

[0047] In the above scheme, by selecting degassed deionized water or an alcohol mixture as the working fluid, the flat wire motor uniform temperature stator system has good vapor-liquid circulation capability.

[0048] In a specific embodiment of the present invention, the number of heterogeneous microchannel array heat pipes 3 corresponds one-to-one with the number of stator slots 12, forming a uniform temperature heat conduction network of the complete slot domain. Under high load, high frequency, and long-term full load conditions, it can effectively control the formation of hot spots in the windings 2 and significantly reduce the temperature difference gradient between turns and between layers of each winding 2.

[0049] The following describes in detail the flat wire motor temperature equalization stator system based on heterogeneous microchannel array heat pipe 3 in an embodiment of the present invention, with reference to a specific implementation method.

[0050] In this embodiment, the stator core 1 adopts a 54-slot structure, the slots 12 of the stator core 12 are open rectangular, the stator core 1 is made of low-loss, high-permeability silicon steel, and the effective axial length is 120mm. A stator yoke heat pipe mounting slot 13 is provided at the yoke slot of each stator slot 12, and stator tooth heat pipe mounting slots 14 are provided at the left tooth root and right tooth root, respectively, for embedding heterogeneous microchannel array heat pipes 3.

[0051] The winding 2 adopts an 8-layer centralized arrangement. The conductor in the winding 2 is oxygen-free copper rectangular enameled wire. The number of turns of the winding 2 is arranged according to the three-phase 8-pole design. After being embedded in the stator slot 12, it is closely attached to the three sides of the heterogeneous microchannel array heat pipe 3. It is electrically insulated from the heterogeneous microchannel array heat pipe 3 by an insulating pad with a PPI greater than 30, forming a near-field heat exchange structure.

[0052] The heterogeneous microchannel array heat pipe 3 includes a first sub-heat pipe 32, a second sub-heat pipe, and a third sub-heat pipe 31 arranged on three sides. The third sub-heat pipe 31 can be referred to as the yoke groove heat pipe, and the first sub-heat pipe 32 and the second sub-heat pipe can be referred to as the toothed groove heat pipe. The thickness of the first sub-heat pipe 32, the second sub-heat pipe, and the third sub-heat pipe 31 is 1.0 mm, the width is the groove width minus 3 mm, and the length is basically the same as the effective length of the stator core 1.

[0053] like Figure 3As shown in Figure 4, the first sub-heat pipe 32, the second sub-heat pipe and the third sub-heat pipe 31 are all closed structures made of copper shells and filled with deaerated deionized water as working fluid. The evaporation end of the third sub-heat pipe 31 is provided with a yoke heat pipe evaporation end wick 312 (i.e., the first wick), specifically, the yoke heat pipe evaporation end wick 312 is arranged on the yoke heat pipe evaporation end shell plate 311, and the condensation end is provided with a yoke heat pipe condensation end wick 314 (i.e., the second wick), specifically, the yoke heat pipe condensation end wick 314 is arranged on the yoke heat pipe condensation end shell plate 315. The yoke heat pipe condensation end shell plate 315 and the yoke heat pipe evaporation end shell plate 311 are both part of the shell of the third sub-heat pipe 31, and the two are arranged opposite to each other; a plurality of yoke heat pipe capillary reflux columns 313 are arranged in a sequential array to form a plurality of yoke heat pipe microchannel vapor chambers 316 and to form a return liquid path. The surface of the column is provided with a hydrophilic coating to enhance the capillary liquid absorption capacity; the first sub-heat pipe The evaporation end of tube 32 and the second sub-heat pipe is provided with a toothed heat pipe evaporation end wick 322 (i.e., the first wick). Specifically, the toothed heat pipe evaporation end wick 322 is arranged on the toothed heat pipe evaporation end shell plate 321. The condensation end is provided with a toothed heat pipe condensation end wick 324 (i.e., the second wick). Specifically, the toothed heat pipe condensation end wick 324 is arranged on the toothed heat pipe condensation end shell plate 325. The toothed heat pipe evaporation end shell plate 321 and the toothed heat pipe condensation end shell plate 325 are both part of the shell of the first sub-heat pipe 32 and the second sub-heat pipe, and they are arranged opposite to each other. Multiple toothed heat pipe capillary reflux columns 323 are arranged in a sequential array to form several toothed heat pipe microchannel vapor chambers 326 and form a return liquid path. The surface of the column is provided with a hydrophilic coating to enhance the capillary liquid absorption capacity.

[0054] The evaporation end is attached to the main heat flow channel of winding 2. The evaporation end receives the heat conducted from winding 2 to the stator core 1 wall. After the working fluid vaporizes, it migrates to the condensation section along the heat pipe microchannel vapor chamber 316 of the yoke / heat pipe microchannel vapor chamber 326 of the tooth. After being coupled and cooled by the water cooling chamber of the stator shell, it condenses into liquid and is returned to the evaporation end through the liquid wick, forming a closed phase change heat transfer cycle.

[0055] The heterogeneous microchannel array heat pipe 3 is fixed to the stator core 1 by silver-based brazing, and the interface is filled with ceramic-based high thermal conductivity adhesive, with an interface thermal resistance of less than 1.5×10⁻ 4 m²·K / W, with a stable structure that meets the vibration life requirements of electric drive systems.

[0056] To improve the electromagnetic performance of the motor, a ferrite composite magnetic flux conduction coating is sprayed on the outer wall of the heterogeneous microchannel array heat pipe 3, which compensates for the magnetic flux interruption area originally caused by the heat pipe insertion and minimizes the change in stator magnetic reluctance.

[0057] In summary, this invention provides a flat-wire motor temperature-equalizing stator system based on heterogeneous microchannel array heat pipes. The system employs a three-sided embedded arrangement of the heterogeneous microchannel array heat pipes, specifically embedding a first sub-heat pipe, a second sub-heat pipe, and a third sub-heat pipe (all of which are ultra-thin H-shaped sheet heat pipes) into pre-set slots in the stator yoke and two tooth sections. These sub-heat pipes, along with the windings, form a U-shaped sandwich-like heat channel. Heat is simultaneously radially conducted from the windings through the first, second, and third sub-heat pipes to the stator core, and then transferred to the water-cooled housing, achieving uniform heat extraction and rapid heat transfer within the stator.

[0058] The first, second, and third sub-heat pipes each have an evaporator end, a condenser end, and several reflux columns inside. The evaporator end is located in the near-field high-heat region of the bonding winding; the condenser end is tightly bonded to the stator core, thus thermally coupling with the water-cooled casing; the reflux columns in the middle divide the inner cavity of the casing into several vapor chambers (i.e., diffusion microchannels), while simultaneously supporting the heterogeneous microchannel array heat pipes. The reflux columns are gradient-distributed along the thickness direction of the sub-heat pipes, and the evaporator end uses a high-capillary-force microporous material, while the condenser end uses a low-resistance macroporous structure, forming a stable and directional vapor-condensate circulation path. This structure can effectively improve the heat pipe thermal cycle efficiency and reduce the start-up temperature difference.

[0059] In this invention, the shells of the first sub-heat pipe, the second sub-heat pipe, and the third sub-heat pipe are made of copper-based composite material and coated with a magnetic permeability coating (such as ferrite powder coating) to compensate for the interference of the heat pipe on the original magnetic circuit of the motor and to avoid affecting the electrical performance of the motor due to the intervention of the heat pipe.

[0060] In this invention, the heterogeneous microchannel array heat pipe is installed and fixed in the stator slot by means of interference fit, brazing or thermal adhesive, so as to ensure its stability and low contact thermal resistance under high vibration and high temperature conditions, and to prevent the heat pipe from failing due to vibration loosening.

[0061] In this invention, the heterogeneous microchannel array heat pipes are in close contact with the stator core, thus forming a coupled heat-conducting network with the motor's water-cooling system. The evaporation end absorbs heat from the winding, while the condensation end conducts heat to the stator core, ultimately achieving heat dissipation through the water-cooled casing. This structure replaces the original heat conduction method with phase change heat transfer, significantly improving the motor's thermal response speed and temperature rise equalization capability.

[0062] The flat-wire electronic temperature-equalizing stator system of this invention is particularly suitable for the S9 operating conditions of high heat flux density, high-frequency start-up, and high torque output in electric drive systems for engineering machinery. It features fast thermal control response, compact structure, and easy maintenance. This system extends winding life, improves the motor's thermal safety margin, and meets the technical requirements of continuous operation under high-intensity conditions.

[0063] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the present invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the present invention.

[0064] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A flat wire motor temperature-equalizing stator system based on heterogeneous microchannel array heat pipes, characterized in that, include: The stator core has several stator slots, and each stator slot has a heat pipe mounting groove on three inner walls. Several heterogeneous microchannel array heat pipes are installed in the heat pipe mounting slots of the corresponding stator slots to form a U-shaped thermal coupling path. Each heterogeneous microchannel array heat pipe has a bidirectional thermal path with phase change heat transfer as the main method and capillary drive as the auxiliary method. The windings are isolated from the heterogeneous microchannel array heat pipes by an insulating structure after they are embedded in the corresponding stator slots.

2. The flat wire motor temperature-equalizing stator system based on heterogeneous microchannel array heat pipes according to claim 1, characterized in that: The stator slot includes a left tooth side slot, a stator yoke slot, and a right tooth side slot arranged in sequence, and the left tooth side slot and the right tooth side slot are arranged opposite to each other. The heterogeneous microchannel array heat pipe includes a first sub-heat pipe, a second sub-heat pipe, and a third sub-heat pipe; the first and second sub-heat pipes are arranged opposite to each other and are respectively disposed in heat pipe mounting slots on the left tooth side groove and the right tooth side groove; the third sub-heat pipe is disposed in a heat pipe mounting slot on the stator yoke groove.

3. The flat wire motor temperature-equalizing stator system based on heterogeneous microchannel array heat pipes according to claim 2, characterized in that: The first sub-heat pipe, the second sub-heat pipe, and the third sub-heat pipe have the same structure, each including: a shell, and a first wick, a second wick, and several return columns disposed within the shell; The first liquid-absorbing core is located at the first end of the shell, forming an evaporation end; The second absorbent core is disposed opposite to the first absorbent core at the second end of the housing, forming a condensation end; Each reflux column is arranged sequentially along the extension direction of the first and second liquid-absorbing cores, and its two ends are respectively connected to the first and second liquid-absorbing cores, dividing the inner cavity of the shell into several vapor chambers, each of which is a fully enclosed phase change heat transfer chamber. The first wick, the second wick, and the reflux column are all porous media, and the mesh size of the first wick is greater than that of the second wick; the pore size of the holes on the reflux column decreases in a stepwise manner from the evaporation end to the condensation end. The working fluid is impregnated inside the first suction core, the second suction core, and each reflux column.

4. The flat wire motor temperature-equalizing stator system based on heterogeneous microchannel array heat pipes according to claim 3, characterized in that: The evaporation end is attached to the winding, and the condensation end is attached to the stator core. The evaporation end receives the heat conducted from the winding to the stator core wall. After the working fluid is vaporized, it migrates along the vapor chamber to the condensation end. After cooling, it condenses into a liquid. The liquid is returned to the evaporation end through the first liquid wick, the second liquid wick, and the return column, forming a closed phase change heat transfer cycle.

5. A flat wire motor temperature-equalizing stator system based on heterogeneous microchannel array heat pipes according to claim 3, characterized in that: Each reflux column has a hydrophilic coating on its surface.

6. The flat wire motor temperature-equalizing stator system based on heterogeneous microchannel array heat pipes according to claim 3, characterized in that: The first, second, and third sub-heat pipes all have H-shaped cross-sections, with grooves at both ends for fitting into the corresponding heat pipe mounting slots.

7. A flat wire motor temperature-equalizing stator system based on heterogeneous microchannel array heat pipes according to claim 3, characterized in that: The shell has a thickness of 0.8mm to 1.2mm, its length is consistent with the effective core length of the stator, and its width is 1 to 3mm less than the width inside the stator slot.

8. The flat wire motor temperature-equalizing stator system based on heterogeneous microchannel array heat pipes according to claim 1, characterized in that: Heterogeneous microchannel array heat pipes and heat pipe mounting slots are fixed together by interference fit, welding or adhesive to form a thermal interface.

9. A flat wire motor temperature-equalizing stator system based on heterogeneous microchannel array heat pipes according to claim 1, characterized in that: The outer surface of each heterogeneous microchannel array heat pipe is coated with a magnetic field conductive coating.

10. A flat wire motor temperature-equalizing stator system based on heterogeneous microchannel array heat pipes according to claim 3, characterized in that: The working fluid is degassed deionized water or a mixture of alcohols.

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